Cumberland County, TN Insulation Payback
Cumberland County attic insulation, by the numbers
Cumberland County sits in IECC climate zone 4 (Mixed-Humid) — heating load in winter and cooling load in summer, both worth taking seriously here. For a currently uninsulated attic, DOE and ENERGY STAR recommend building up to R-60. Topping up a typical 1,000-square-foot attic from bare joists (R-2) to R-60 runs an estimated $3,480, and saves about $1,318 a year in heating and cooling — a payback around 2.6 years. Topping up the attic pays for itself fast here.
Heating vs. cooling in Cumberland County
Split it out and it's roughly $1,175 a year on the heating side, $143 on cooling. By estimated insulation savings, Cumberland County lands in the 40th percentile nationally. Zone 4 alone covers 825 counties in this dataset, and Cumberland County comes in 550th by savings. Tennessee averages $1,258/year across the counties tracked here; Cumberland County comes in 5% higher.
Cumberland County's actual weather, not a national average
The heating and cooling degree days behind this estimate — 4,394 HDD and 890 CDD (base 65°F, 1991-2020 normals) — come from CROSSVILLE MEM AP, TN US, the nearest NOAA station with published normals, 4.8 miles from Cumberland County's center. That combined heating-and-cooling load ranks Cumberland County 2096th nationally by total degree days — the 34th percentile. One local detail the R-value alone won't tell you: Cumberland County sits in moisture regime A (humid), which can affect the vapor-barrier choice.
If the attic isn't bare
If Cumberland County's attic already has 3-4 inches of old insulation (about R-11) rather than bare joists, the recommended target drops to R-49. That smaller top-up costs around $2,280 and saves an estimated $192/year — payback about 11.9 years. Call this borderline rather than a clear win.
Quotes and materials for this job
Real bids depend on how easy the attic is to reach and whether old insulation needs removing first, so treat $3,480 as a starting estimate for a Cumberland County job, not a quote. Expect at least a $600 minimum charge from most contractors.
Where these figures come from
Cumberland County's R-60 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-60 is the target here specifically.